$.set= $.klass()
$.set.prototype=
{   init: function( vals ){
        this.$= $.hash( {}, '$' )
        if( vals ) this.merge( vals )
        return this
    }
,   each: function( proc, self ){
        this.$.each( function( val, key ){
            return proc.call( this, val, val )
        }, self || this )
        return this
    }
,   get: function( name ){
        return ( ':' + name ) in this.$
    }
,   merge: function( set ){
        var hash= this.$
        set.each( function( val, key ){
            hash[ ':' + val ]= val
        } )
        return this
    }
,   destroy: function(){
        delete this.$
    }
}